Try this:

Exit Thunderbird Access profile folder of second profile. Delete the 'global-messages-db.sqlite' file.

Start Profile Manager select second profile click on 'start Thunderbird'

Did it start ok ?

I attempted to follow your procedure and it resulted in the same problem I had earlier. I can open my first profile without the profile mgr. I had been able to open the second profile by using "run" and "thunderbird.exe -p" and entering the name and profile file. Now, I cannot open either with the Profile Mgr, even though I enter the correct profile name and file.

When I went to 'global-messages-db.sqlite' files using search there were many. I deleted those with no content. They must have been residue left from the many times I had attempted to use the Profile Mgr.

I did transfer the profiles and E-Mail history files needed to my notebook running Win7 Pro and I can now open both profiles using the notebook. This was an easy setup and worked the way I had accomplished this in past versions of Windows. Windows 10 Pro uses the Windows 8 alternate to run Thunderbird. I have attempted to use earlier versions, but get the same results.

I don't know why the Profile Mgr in Windows 10 Pro will not recognize the same files that I used successfully today in Profile Mgr in my notebook.

re :When I went to 'global-messages-db.sqlite' files using search there were many. I deleted those with no content.

So you did not delete any that were of a size. I suggest you delete all and retry. It is only a database for global search which would repopulate when Thunderbird restarts. I asked you to remove it because in some cases, for an unknown reason, it has caused Thunderbird to not open on a profile.

I removed all files found in 'global-messages-db.sqlite' search from all drives. External drives were removed. I can still get to Profile Mgr using "RUN" from the start menu and I did list the two Profile names and and associated Profile files. I still cannot use the Profile Mgr to access Profiles. I have tried to change thunderbird to run in windows 7 in this windows 10 machine with no change in operation. It naturally runs in Windows 8.

When I close the Profile Mgr after setup with both profiles, and reopen it using the Thunderbird Icon on my desktop, the Profile Mgr opens, but it has no Profiles listed.

I can still access the first Profile using the desktop icon. I cannot access the second using the "RUN" function and Profile Mgr, as I was able to do prior to the most recent Windows 10 update.

This is a computer with an ASUS Z97-E motherboard and Intel i7 processor - 16TB of RAM - and Windows 10 Pro with the latest updates. It has over 1.5 TB of internal hard drives. As I noted before, the profile files work properly when I copy them to my Windows 7 notebook and set up the Profile Mgr on that HP Intel i5 machine.

how about you access the profile manager from the troubleshooting information on the help menu.

Click the About:profiles entry on the bottom of the first group of information.

While not exactly your issue I discuss this new approach to managing profiles in this blog post. https://thunderbirdtweaks.blogspot.com/2019/09/i-lost-my-profilemail-on-update-to.html

Just for information, I attempted to use Help Menu and Troubleshooting. The message received was: "An unexpected error has prevented your changes from being saved."

I restarted Thunderbird and tried the same with the same results. I'll read the blog post and see if there is any further information.

open the error console Ctrl+ Shift+J Clear it.

Now try the change again. was there an entry in the error console corresponding to the "unexpected error? What was it. (right click to get copy options for errors)

There were several entries related to Chrome. I do not use Chrome.

There were several noted from today including:

WebExtensions: Loading add-on preferences from C:\Users\User\AppData\Roaming\Thunderbird\Profiles\ko0f7i5d.default\extensions\{e2fda1a4-762b-4020-b5ad-a41df1933103}.xpi ext-legacy.js:190 WebExtensions: Firing profile-after-change listeners for {e2fda1a4-762b-4020-b5ad-a41df1933103} ext-legacy.js:194 Use of Mutation Events is deprecated. Use MutationObserver instead. calendar-views.js:97:9

2019-11-23 15:48:58 gloda.index_msg ERROR Problem entering folder: datareporting, skipping. Error was: undefined:631: [Exception... "Component returned failure code: 0x80520015 (NS_ERROR_FILE_ACCESS_DENIED) [nsIMsgLocalMailFolder.getDatabaseWithReparse]" nsresult: "0x80520015 (NS_ERROR_FILE_ACCESS_DENIED)" location: "JS frame :: resource:///modules/gloda/index_msg.js :: _indexerEnterFolder :: line 631" data: no]

I don't know if this clarifies anything. I did note that the profile mentioned in the initial message -Profiles\ko0f7i5d.default- was my primary profile for the first E-Mail site, but I was not allowed to add it when I had to reenter everything earlier. Another Profile was being used, but appeared to have everything up to date.

Just a note. The same content is found in the error console after emptying and then attempting to use Profile Mgr. The error console remains empty until I try to set up my profiles.

Nomenclature is biting you.

Google has a browser called Chrome. It is a commercial version of the open Source Chromium Browser. Not relevant to Thunderbird really, but in the mass perception it is "Chrome"

Then there is the usage in Graphical user interfaces that goes back decades referring to everything in the user interface other than the content (be it a document or a web page) as the chrome. A term derived from the historical use of Chrome on cars. So developers basically considered their additions to the content like chrome on cars, the shiny bits that added nothing to the content.

Now I dd ask you to clear the error console. (the trash can icon) and try again, not read what was there. I am trying to see if the profile update that generates the error dialog also logs something.

However the error message about Gloda may well indicate the issue is at least partially with external software. GLoda or 'global-messages-db.sqlite' is a very large file that is used by nothing but Thunderbird. That Thunderbird is getting denied access error would indicate something else is locking the file.

Generally this sort of contention is caused by one of two things, but as you have deleted the file there might be a third.

Open the activity manager (in the on the menu on the toolbar) wait a little and see if there are lines about determining what to index and similar terms that would show the rebuild of GLODA is still continuing.

If not, we fall to the common two;

1. Anti virus. Place an exception in the anti virus for the Thunderbird profiles folders. If your using defender place an exception for the Thunderbird process.
2. Synchronising services. The folder is being synchronised by something like Google drive, of a streaming backup. Streaming backups and Thunderbird are very bad, they not only cause issues, but rarely actually backup anything useful.

I would also guess from the first error that your profile is located in C:\Users\User\AppData\Roaming\Thunderbird\Profiles\ko0f7i5d.default

Again use the troubleshooting information, this time use the show profile button to determine exactly which profile folder you are using as your final comment indicated you though you were using something else.

Could you provide some info. Access: C:\Users\User\AppData\Roaming\Thunderbird folder

open the 'profiles.ini' file using a text editor like Notepad and post an image showing contents. Also please open 'installs.ini' file using a text editor like Notepad and post an image showing contents.

Here are the two files requested. Profiles.ini [General] StartWithLastProfile=1

[Profile0] Name=default IsRelative=1 Path=Profiles/ko0f7i5d.default Default=1

Install.ini [8216C80C92C4E828] Default=Profiles/ko0f7i5d.default Locked=1

The 'profiles.ini' file has no knowledge of the second profile. That explains why it cannot open it.

Exit Thunderbird.

Access: C:\Users\User\AppData\Roaming\Thunderbird\Profiles folder. You will see: ko0f7i5d.default

But is there another profile name ? If yes: Open Profile Manager click on 'Create Profile' Click on 'Next' Enter a name for the second Profile eg: Prof2 click on 'Choose Folder' select the name of the second profile which is in : C:\Users\User\AppData\Roaming\Thunderbird\Profiles folder. click on 'Select Folder' button click on 'Finish'

You should now be able to select that second profile name.

It should be understood that every time I open Profile Mgr using RUN, neither Thunderbird profile is shown. When I have attempted to set up one or the other (or both) I try to open it and the computer shows some activity, but even waiting 10 minutes does not result in opening of the Thunderbird profile selected using the desktop shortcut. This is the profile seen in profile.ini. I have attempted to accomplish setup of the Profile Mgr using Windows 8 and Windows 7 settings.

When I do open Profile Mgr using RUN, I have to reboot or try something else to get into my main profile. Otherwise, I continue to get the empty Profile Mgr when I use the desktop shortcut. The profile.ini and install.ini appear the same as I sent earlier. With each failed attempt to set up the Profile Mgr I have gone back to search for "global-messages-db.sqlite" in all internal drives and deleted them. This has only involved Drive C and, because of the file size, it appears to be a failed setup.

I have booted the computer with no external drives connected and shut down all network computers that may have Thunderbird on them. Even under these conditions I get the same response when attempting to set up the Profile Mgr. I am running Thunderbird as Administrator.

My 'profiles.ini' shows something different to your 'profiles.ini'.

Please try this: Make a copy of 'profiles.ini' and put it on desktop as a temp backup.

Then in 'profiles.ini' file make it look like the text shown between the lines:

[Install8216C80C92C4E828] Default=Profiles/ko0f7i5d.default Locked=1

[Profile0] Name=default IsRelative=1 Path=Profiles/ko0f7i5d.default Default=1

[General] StartWithLastProfile=1 Version=2

Then save the file and start profile manager. Please report back on results.

I made the suggested change and results were the same. However, with that change I could not get past the Profile Mgr screen. I attempted to use all prior methods to bypass Profile Mgr, but none - including reboot - got rid of it.

I finally went to profile.ini and deleted everything. This allowed me to at least get back to this E-Mail address.

After making these changes (but prior to deleting profile.ini), for some reason my computer started to boot up to other than my Drive C:. I now have to go into the bios at startup and locate the drive C in a separate list. It then boots correctly. I have contacted ASUS to determine why all of my drives are not shown in the boot priority list in the bios. I may have corrupted the bios. A higher level ASUS tech support rep will be getting back to me within 24 to 48 hours. I have also noted an error in my Device Mgr "AMDA00 Interface" - "Windows cannot start this hardware device because its configuration information (in the registry) is incomplete or damaged (Code 19)". This may be related to the problems.

Can you try adding -allow-downgrade to your command line? E.g. thunderbird.exe -allow-downgrade -p

The problems described above have been resolved - Finally!

Since I could not get into Thunderbird with the last settings provided, I decided to empty the profile.ini file completely. When I restarted my computer to try to resolve the boot drive issue - which I did - I then closed the computer down again and rebooted. When I opened in Windows 10 Pro and tried again to open Thunderbird, I noticed that the Profile Mgr came up and it had one E-Mail file shown. I tried to enter and was successful. I then added the second Profile and it worked fine.

I then reopened profile.ini and found:

[Install8216C80C92C4E828] Default=Profiles/ko0f7i5d.default Locked=1

[Profile1] Name=ATTGlobal IsRelative=1 Path=Profiles/gk61ge5s.ATTGLOBAL

[Profile0] Name=ATT IsRelative=1 Path=Profiles/ko0f7i5d.default Default=1

[General] Version=2 StartWithLastProfile=0

This does show both profiles and they now work well.

Thanks to all that have worked so hard to resolve this issue. The way I would handle this in the future would be to empty the profile.ini file and reboot a few times to see if this corrected the issue.

Thanks again.